Variable stiffness flexure

ABSTRACT

An intrauterine device includes a central support member, first and second internal flexures and first and second external flexures. The first and second internal flexures each include a first section having a first stiffness, a second section having a second stiffness, and third section having a third stiffness, wherein the second stiffness is more flexible than the first and third stiffness and wherein the first section of each internal flexure is coupled to the central support member. The first and second external flexures are coupled to the central support member and coupled to the third sections of the first and second internal flexures, the first and second external flexures in combination with the first and second internal flexures being configured to extend from a collapsed position parallel to the central support member to a deployed position flexing away from the central support member.

RELATED APPLICATION DATA

This application is a continuation of pending U.S. patent applicationSer. No. 13/447,728, filed Sep. 16, 2012, the priority of which isclaimed under 35 U.S.C. §120, and the contents of which are incorporatedherein by reference as though set forth in full.

BACKGROUND

Intrauterine medical devices are often inserted through a patient'scervix and then expanded inside the patient's uterus. For example, auterine ablation procedure may be performed by inserting a sheaththrough the cervix and then extending an applicator through the distalend of the sheath and expanding the applicator in the uterus. Theapplicator is expanded inside the patient, out of view of the personperforming the procedure. Reliable and proper deployment of theapplicator and subsequent robustness of the device are important toavoid complications and potential injury to the patient. Additionally,the applicator should reliably contract back into the sheath for removalfrom the patient.

SUMMARY

Aspects and embodiment are directed to reducing the diameter of thesheath of an intrauterine device while maintaining the strength androbustness of the device. Reducing the diameter of the sheath of anintrauterine device improves its ease of insertion and decreases patientdiscomfort.

According to one aspect, a device includes a central support member,first and second internal flexures, and first and second externalflexures. The device may be an intrauterine device. The first and secondinternal flexures each include a first section having a first stiffness,a second section having a second stiffness, and third section having athird stiffness, wherein the second stiffness is more flexible than thefirst and third stiffness and wherein the first section of each internalflexure is coupled to the central support member. The first and secondexternal flexures are each coupled to the central support member and areeach coupled to the third section of the respective first and secondinternal flexures. The first and second external flexures, incombination with the first and second internal flexures, are configuredto extend from a collapsed position parallel to the central supportmember to a deployed position flexing away from the central supportmember. In one embodiment, the device is an endometrial ablation device.According to one feature, stiffness refers to the bendingcharacteristics of the flexure.

According to one embodiment, the first and second internal flexuresfurther include a fourth section having a fourth stiffness and a fifthsection having a fifth stiffness. The fourth section is positionedbetween the first section and the second section and the fifth sectionis positioned between the second section and the third section. Thefourth and fifth stiffnesses are more flexible than the first and thirdstiffnesses and less flexible than the second stiffness. In oneembodiment, the fourth and fifth stiffnesses taper, decreasing instiffness toward the second section.

In another embodiment, the device also includes a bridge coupled betweenthe first and second external flexures. The bridge may be configured tofold in the first position and to at least partially extend in thesecond position. In one embodiment, the device includes a mesh arraysurrounding the first and second external flexures, the first and secondinternal flexures and the central support member.

According to another aspect, a device includes a central support member,first and second internal flexures, and first and second externalflexures. In one embodiment, the device is an intrauterine device. Thefirst and second internal flexures each include a first section having afirst stiffness and a second section having a second stiffness, whereinthe second stiffness is less than the first stiffness and wherein thefirst section of each internal flexure is coupled to the central supportmember. The first and second external flexures are each coupled to thecentral support member and are each coupled to the second section of therespective first and second internal flexures. The first and secondexternal flexures, in combination with the first and second internalflexures, are configured to extend from a collapsed position parallel tothe central support member to a deployed position flexing away from thecentral support member. In one embodiment, the device is an endometrialablation device.

According to one aspect, a device includes a central support memberhaving a center line, first and second internal flexures each includingfirst and second sections, and first and second external flexures. Thefirst section is positioned adjacent to the second section, and in oneexample, the first section is stacked on the second section. The firstsection includes a middle portion, and the middle portion has a C-shape,wherein the middle portion curves inward toward a center line and curvesoutward toward the second stacked section. The first and second externalflexures are each coupled to the central support member and each couplednear a distal end of the respective first and second internal flexures.The first and second external flexures, in combination with the firstand second internal flexures, are configured to extend from a collapsedposition parallel to the central support member to a deployed positionflexing away from the central support member. In one embodiment, thedevice is an intrauterine endometrial ablation device.

In one embodiment, the intrauterine device also includes a sheathconfigured to enclose the central support member, the first and secondinternal flexures and the first and second external flexures when in acollapsed and retracted position. In another embodiment, the deviceincludes a mesh array supported by the first and second externalflexures, the first and second internal flexures and the central supportmember. The mesh array may be comprised of a conductive material.

According to another aspect, a device includes a central support member,first and second sets of internal flexures, and first and secondexternal flexures. The first set of internal flexures includes twointernal flexures, and the proximal end of each internal flexure iscoupled to the central support member at a first position. The secondset of internal flexures includes two internal flexures, and theproximal end of each internal flexure is coupled to the central supportmember at a second position, wherein the second position is distal tothe first position. The first and second external flexures are eachcoupled to the central support member and are each coupled to distalends of the first and second sets of internal flexures. The first andsecond external flexures, in combination with the first and second setsof internal flexures, are configured to extend from a collapsed positionparallel to the central support member to a deployed position flexingaway from the central support member.

According to one aspect, a device includes a central support member,first and second internal flexures, and first and second externalflexures. In one embodiment, the device is an intrauterine device. Thefirst and second internal flexures each include a first section having afirst thickness, a second section having a second thickness, and thirdsection having a third thickness, wherein the second thickness is lessthan the first and third thicknesses and wherein the first section ofeach internal flexure is coupled to the central support member. Thefirst and second external flexures are each coupled to the centralsupport member and are each coupled to the third section of therespective first and second internal flexures. The first and secondexternal flexures, in combination with the first and second internalflexures, are configured to extend from a collapsed position parallel tothe central support member to a deployed position flexing away from thecentral support member. In one embodiment, the device is an endometrialablation device.

In one embodiment, the central support member includes two or moresupport members coupled together. The support members may move relativeto one another. The support members may be telescoping support members.In one example, the support members may be slidably coupled together.According to one feature, the first and second internal flexures areattached to a first support member of the central support member, andthe first and second external flexures are attached to a second supportmember of the central support member.

In one embodiment, the first and second internal flexures furtherinclude a fourth section having a fourth thickness and a fifth sectionhaving a fifth thickness. The fourth section is positioned between thefirst section and the second section and the fifth section is positionedbetween the second section and the third section. The fourth and fifththicknesses are thinner than the first and third thicknesses and thickerthan the second thickness. In one embodiment, the fourth and fifththicknesses taper, decreasing in thickness toward the second section. Inanother embodiment, the fourth and fifth sections are triangular shaped.

According to one embodiment, the device also includes a bridge coupledbetween the first and second external flexures. The bridge may beconfigured to fold in the first position and to at least partiallyextend in the second position. According to another embodiment, thedevice also includes a sheath configured to enclose the central supportmember, the first and second internal flexures and the first and secondexternal flexures when in the first position.

In one embodiment, the device also includes a mesh array surrounding thefirst and second external flexures, the first and second internalflexures and the central support member. The mesh array may be comprisedof a conductive material. In another embodiment, the central supportmember is a tube.

According to another aspect, a device includes a central support member,first and second internal flexures, and first and second externalflexures. In one embodiment, the device is an intrauterine device. Thefirst and second internal flexures each include a first section having afirst thickness and a second section having a second thickness, whereinthe first thickness is less than the second thickness and wherein thefirst section of each internal flexure is coupled to the central supportmember. The first and second external flexures are each coupled to thecentral support member and are each coupled to the second section of therespective first and second internal flexures. The first and secondexternal flexures, in combination with the first and second internalflexures, are configured to extend from a collapsed position parallel tothe central support member to a deployed position flexing away from thecentral support member. In one embodiment, the device is an endometrialablation device.

According to another aspect, a method of manufacturing an intrauterinedevice includes providing a central support member, providing first andsecond internal flexures to include a first section having a firststiffness, a second section having a second stiffness, and third sectionhaving a third stiffness, wherein the second stiffness is more flexiblethan the first and third stiffness, providing first and second externalflexures, attaching the first section of each internal flexure to thecentral support member, attaching, at a first location, the first andsecond external flexures to the central support member, and attaching,at a second location, the first and second external flexures to thethird section of the respective first and second internal flexures.

According to one embodiment, providing a central support member includesforming a first hollow elongate tubular member, forming a second hollowtubular member, and coupling the first hollow tubular member with thesecond hollow tubular member. According to another embodiment, providingof the first and second internal flexures includes forming the first andsecond flexures such that the first section has a first thickness, thesecond section has a second thickness, and the third section has a thirdthickness. According to a further embodiment, the forming is done byphotoetching.

Still other aspects, embodiments, and advantages of these exemplaryaspects and embodiments, are discussed in detail below. Embodimentsdisclosed herein may be combined with other embodiments in any mannerconsistent with at least one of the principles disclosed herein, andreferences to “an embodiment,” “some embodiments,” “an alternateembodiment,” “various embodiments,” “one embodiment” or the like are notnecessarily mutually exclusive and are intended to indicate that aparticular feature, structure, or characteristic described may beincluded in at least one embodiment. The appearances of such termsherein are not necessarily all referring to the same embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of at least one embodiment are discussed below withreference to the accompanying figures, which are not intended to bedrawn to scale. The figures are included to provide illustration and afurther understanding of the various aspects and embodiments, and areincorporated in and constitute a part of this specification, but are notintended as a definition of the limits of the invention. In the figures,each identical or nearly identical component that is illustrated invarious figures is represented by a like numeral. For purposes ofclarity, not every component may be labeled in every figure. In thefigures:

FIG. 1 is a side elevation view of an intrauterine therapy applicationdevice with an applicator in a retracted position according to aspectsof the invention;

FIG. 2 is a side elevation view of the intrauterine therapy applicationdevice of FIG. 1, showing the applicator in a deployed positionaccording to aspects of the invention;

FIG. 3A is a perspective view of an embodiment of an intrauterinetherapy application device applicator in a deployed position, accordingto aspects of the invention;

FIG. 3B is an elevation view of an embodiment of an intrauterine therapyapplication device applicator in a deployed position, according toaspects of the invention;

FIG. 4 is a perspective view of an embodiment of a portion of anintrauterine therapy application device applicator in a collapsedposition according to aspects of the invention;

FIG. 5 is a perspective view of an embodiment of a portion of anintrauterine therapy application device applicator showing internalflexures according to aspects of the invention;

FIG. 6 is a blown up view of an embodiment of a section of an internalflexure having a varying thickness according to aspects of theinvention;

FIG. 7 is a perspective view of an embodiment of a portion of anintrauterine therapy application device applicator showing internalflexures of varying thickness according to aspects of the invention;

FIG. 8 is a blown up view of an embodiment of a section of an internalflexure having varying thickness according to aspects of the invention;

FIG. 9A is a side view of a section of an embodiment of an internalflexure having varying thickness according to aspects of the invention;

FIG. 9B is a side view of a section of an embodiment of an internalflexure having varying thickness according to aspects of the invention;

FIG. 10 is a side elevation view of a portion of an embodiment of anintrauterine therapy application device applicator according to aspectsof the invention;

FIGS. 11A-11B show a section of an the internal flexure according toaspects of the invention;

FIG. 12 is a flow chart of a method of manufacturing an intrauterinetherapy application device applicator, according to aspects of theinvention.

FIG. 13 is a perspective view of an embodiment of an intrauterinetherapy application device applicator showing a portion of internalflexures according to aspects of the invention;

FIG. 14 is an elevation view of a portion of an embodiment of a centralsupport member according to aspects of the invention;

FIG. 15 is an elevation view of a portion of an embodiment of aninternal flexure according to aspects of the invention;

FIG. 16 is a blown up view of a portion of an embodiment of a centralsupport member and internal flexures according to aspects of theinvention;

FIG. 17 is a perspective view of an embodiment of an intrauterinetherapy application device applicator according to aspects of theinvention;

FIG. 18 is a perspective view of an embodiment of an intrauterinetherapy application device applicator having two sets of internalflexures according to aspects of the invention;

FIG. 19A is a perspective view of a portion of an embodiment of anintrauterine therapy application device applicator, according to aspectsof the invention;

FIG. 19B is an elevation view of a portion of the embodiment of anintrauterine therapy application device applicator of FIG. 19A furtherincluding a mesh array, according to aspects of the invention;

FIG. 20A is a perspective view of a portion of an embodiment of anintrauterine therapy application device applicator, according to aspectsof the invention;

FIG. 20B is an elevation view of a portion of the embodiment of anintrauterine therapy application device applicator of FIG. 20A furtherincluding a mesh array, according to aspects of the invention; and

FIG. 20C is an elevation view of a portion of an intrauterine therapyapplication device applicator having a mesh array, according to aspectsof the invention.

DETAILED DESCRIPTION

Various aspects of at least one embodiment are discussed below withreference to the accompanying figures, which are not intended to bedrawn to scale. The figures are included to provide illustration and afurther understanding of the various aspects and embodiments, and areincorporated in and constitute a part of this specification, but are notintended as a definition of the limits of the invention. In the figures,each identical or nearly identical component that is illustrated invarious figures is represented by a like numeral. For purposes ofclarity, not every component may be labeled in every figure.

According to aspects of this disclosure, various structures and methodsare provided herein for decreasing a size or diameter of an intrauterinetherapy application device in a retracted position, while maintainingits strength and stiffness in expanded and deployed positions. In atleast one embodiment, various structures and methods are provided formaintaining the strength of a deployment mechanism of an intrauterinetherapy application device by varying the stiffness of at least aportion of the individual flexures of the deployment mechanism.

According aspects of this disclosure, structure and methods are providedto decrease the stiffness of at least a portion of some of the flexuresof a deployment mechanism of an intrauterine therapy application device,without increasing the risk of buckling of the deployment mechanism ofintrauterine therapy application device. One advantage of decreasing thestiffness of least a portion of some of the flexures of the deploymentmechanism of the intrauterine therapy application device is a reducedsize or diameter of the intrauterine therapy application device incollapsed position or a retracted into a sheath position, which providesfor a smaller-diameter sheath while still maintaining the deploymentmechanism's strength and stiffness in collapsed and deployed positions.Another advantage is a smaller outer diameter sheath may reduce patientdiscomfort and decrease the potential for cervical injury duringinsertion into the uterus.

By way of introduction and referring to the Figures, illustrated in FIG.1 is an intrauterine therapy application device includes an applicator102, a sheath 104, and an RF generator 110. According to one embodiment,the sheath is inserted through the patient's cervix. The applicator maybe retracted in a collapsed position within the sheath for insertioninto the patient's cervix. The sheath may be inserted through thepatient's cervix, and when the distal end 104 a of the sheath is insidethe uterus, the applicator may be extended into the uterus in acollapsed position and expanded into a deployed state in the uterus.FIG. 3B illustrates an intrauterine therapy application deviceapplicator 102 in a deployed position and having a mesh array 142.Decreasing the size, such as the width in a collapsed position of theapplicator allows for use of a smaller-diameter sheath. A sheath havinga smaller outer diameter may reduce patient discomfort, and alsodecrease the potential for cervical injury during insertion through thecervix and into the uterus. In some embodiments, the deploymentmechanism includes internal flexures (see 160, 162 of FIG. 3A) andexternal flexures (see 156, 158 of FIG. 3A). In a deployed position,external flexures (156, 158 of FIG. 3A) define the outer contour of theapplicator, and internal flexures (160, 162 of FIG. 3A) facilitatereliable deployment of the applicator from the sheath into a collapsedposition and into a deployed state as well as retraction of theapplicator into the collapsed position and into the sheath.

Referring to FIG. 3A, the intrauterine therapy application device 100can be spread open by driving an internal central support member 154forward relative to an external central support member 152. Depending onthe forces provided by the drive mechanism used to actuate the internalcentral support member, the applicator may or may not open to itsmaximum width. For example, consider using a screw drive to driveforward the internal central support member 154 and to spread theinternal 160, 162 and external 156, 158 flexures. The travel of thecentral support member (and thus the deployment of flexures) is rigidlycoupled to the travel of the screw drive. Even if some mechanicalrestriction prevents the internal and external flexures from spreadingto their full width, the screw drive will continue to try to advance theinternal central support member. One disadvantage is that this screwdrive can generate significant spreading force in the flexures, and itcan result in heavy stress on the flexures.

As a second example, consider introducing a compliant element, such as aspring, between the screw drive and the internal central support member154. The spring transmits force from the screw drive to the internalcentral support member, so that if the external flexures areunrestricted, the flexures will deploy normally to their full width.Alternatively, in the event that the tips of the flexures somehow becomerestricted, the spring can absorb the screw's travel, allowing theflexures to rest at a sub-maximum width without heavy stress. Thus, theintroduction of a compliant element between the screw drive and theinternal support member allows for a simple drive mechanism that drivesa deployment mechanism that can automatically open to variable maximumwidths (i.e. opening to fill a cavity of unknown size). It also controlsthe spreading force that the deployment mechanism is able to generate.

Functionally, the purpose of the deployment mechanism of theintrauterine therapy application device is to spread the mesh array 142from a collapsed state into a deployed state. The mesh array is knitfrom elastic yarn, so a certain level of force is needed simply tospread the mesh array to the desired shape. On top of stretching themesh array, the deployment mechanism must be capable of generatingadditional spreading force to ensure that the deployment mechanism stillopens properly if resistance is encountered. Simultaneously, it isdesirable for the deployment mechanism to be as small as possible and tobe as mechanically durable as possible.

One approach considered by the Applicants for a deployment mechanismused internal flexures made of a single-thickness piece of material.These single-thickness internal flexures had a relatively consistentstiffness and, therefore, a relatively consistent bending radius. Theresulting deployed shape of the internal flexure was approximately anarc. For most scenarios, this single-thickness internal flexure provideda structure that was sufficiently mechanically durable. However, thisarc can be susceptible to damage under mechanically disadvantageousloading conditions. There are a few solutions that were considered toreduce this susceptibility.

A first approach to improving the durability of the deployment mechanismis that the strength of the internal flexure could be increased so thata greater mechanical stress would be required to damage the internalflexure. One way to do this would be to add material to the internalflexure, either increasing the thickness or height of the internalflexure. However, a drawback of this approach is that it would increasethe overall size of the deployment mechanism. Additionally, increasingthe thickness of the internal flexure could increase the rigidity of theinternal flexure so much that it would be unable to conform to thedesired arc profile without permanently deforming.

A second approach to improving the durability of the deploymentmechanism is to make the entire internal flexures morecompliant/resilient so that the deployment mechanism can enduresignificant mechanical manipulation and displacement without undergoingpermanent deformation. This approach could be achieved, for example,using either a thinner or lower-height internal flexure, by selecting amore flexible material for the internal flexures, or decreasing a widthof the entire internal flexures. While this approach could reduce thesize of the deployment mechanism, the reduction in the resilience of theentire flexures of the deployment mechanism can be a problem. Applicantsdiscovered that prototypes with such compliant flexures though flexibleand resilient, lacked the mechanical strength needed to sustain thedesired spreading forces and deploy the mesh array. Applicantsdiscovered that prototypes with such compliant flexures result indecreased integrity of the deployment mechanism of the applicator and anincreased chance of buckling of the deployment mechanism of theapplicator during deployment from the sheath and/or collapsing of theapplicator. When an applicator buckles, the flexures of the deploymentmechanism bend at an unintended angle and may lead to an overall shapeof the deployment mechanism and the applicator being compromised. Afurther disadvantage of such modified flexures and deployment mechanismis that the buckling of the applicator may also lead to difficulty orinability to retract the applicator into its sheath or expand theapplicator into its expanded position.

To generate adequate spreading forces in a smaller, sufficiently robustdeployment mechanism, Applicants discovered a more complex approach thatsolves the above-noted issues. Specifically, Applicants discovered thatit is desirable for a distal portion of the internal flexures to be madestronger, but for the internal flexures to still be capable of bendingenough to generate sufficient lateral spreading of the mesh array. Onesolution considered was a strong, rigid internal flexure, connected by ahinge to the central support member. But a robust hinge would bedifficult to fit in such a small space and therefore was not used.Another solution is to build a living hinge into the internal flexure.This structure and arrangement has the advantages of being compact,strong, and favorable from a manufacturing perspective. Ultimately, withsuch a structure and arrangement, the same array spreading performanceand improved mechanical durability can be delivered in a smaller packagethan a single-thickness flexure design. The performance improvement ofthis deployment mechanism is most noticeable when the deploymentmechanism is actuated by the compliant drive mechanism describedearlier.

Referring now to the Figures, a detailed description of variousembodiments of such an intrauterine therapy application device,deployment mechanism, and applicator structure will now be discussed.FIG. 1 is a side elevation view of an intrauterine therapy applicationdevice 100 with an applicator 102 in a retracted position inside ahollow sheath 104. The intrauterine therapy application device 100includes a handle 106, and is coupled via a cable 120 to aradiofrequency signal generator 110 and via a tube 128 to a vacuumsource 112. The radiofrequency generator 110 generates an electricalsignal, for example a radiofrequency signal, and transmits it to theapplicator 102 through the cable 120, which is ultimately coupled to theapplicator through the handle 106. The vacuum source 112 is connected tothe handle 106 at the vacuum port 122 and creates suction in the distalend of the applicator 102. According to one feature, the distal end 104a of the sheath 104 of the intrauterine therapy application device 100is configured to be inserted into a patient's cervix.

The handle 106 includes a distal grip 124 and a proximal grip 126.During use, the proximal grip 126 is squeezed toward the distal grip124, to cause the applicator 102 to extend out from the sheath 104, asshown in FIG. 2. As shown in FIG. 2, the applicator 102 is extended outfrom the sheath 104 in a collapsed position. As the applicator 102extends out from the sheath 104 in the collapsed position, it alsoexpands as shown in the perspective view of the deployed applicatorillustrated in FIGS. 3A and 3B.

FIG. 3A is a perspective view of a portion of an intrauterine therapyapplication device applicator 102 in a deployed position, according toan embodiment of the invention. The applicator 102 includes an externalcentral support member 152, an internal central support member 154,external flexures 156 and 158 and internal flexures 160 and 162. Theproximal end of the internal central support member 154 is coupled tothe distal end of the external central support member 152, so as toprovide a telescoping arrangement. The proximal ends 156 a and 158 a ofthe external flexures 156 and 158 are attached to the outside of theexternal central support member 152 near the distal end of the externalsupport member 152. The proximal ends 160 a and 162 a of the internalflexures 160 and 162 are attached to the outside of the internal centralsupport member 154, near the proximal end of the internal centralsupport member 154. It is to be appreciated, as will be discussed belowfor example with respect to FIGS. 14-16 that in other embodiments, theproximal ends 160 a and 162 a of the internal flexures 160 and 162 maybe attached to the inside of the internal central support member 154, orthe proximal ends 160 a and 162 a of the internal flexures 160 and 162may be attached into the wall of the internal central support member154. The external flexures 156 and 158 and the internal flexures 160 and162 are attached to the external 152 and internal 154 support memberssuch that the external flexures 156 and 158 and internal flexures 160and 162 flexures lie in the same plane.

The external flexures 156 and 158 in one position extend outward awayfrom being parallel with the central support members 152 and 154 to forma V-shape. According to one embodiment, the external flexures 156 and158 extend laterally away from the external central support member 152,flaring outwards toward the distal ends 156 b and 158 b. Similarly, theinternal flexures 160 and 162 extend laterally away from the internalcentral support member 154, forming a flared V-shape. The secondsections 160 b and 162 b of the internal flexures 160 and 162, adjacentto the proximal ends 160 a and 162 a, gradually extend laterally awayfrom the internal central support member 154. A third section 160 c and162 c of each internal flexure 160 and 162 extends substantiallylaterally and longitudinally away from the internal central supportmember 154. The distal end 160 d of the first internal flexure 160 isattached to a distal end 156 b of the first external flexure 156, and adistal end 162 d of the second internal flexure 162 is attached to thedistal end 158 b of the second external flexure 158.

As shown in FIG. 3A, the central support member of the device applicator102 includes external central support member 152 coupled internalcentral support member 154. In other embodiments, the applicator 102 mayinclude three or more support members coupled together. The external 152and internal 154 central support members may move relative to oneanother. In one example, the external 152 and internal 154 centralsupport members may be telescoping support members. In another example,the external 152 and internal 154 central support members may beslidably coupled together.

According to aspects of the device, a transverse ribbon 164 can extendbetween the distal ends 156 b and 158 b of the external flexures 156 and158. In one embodiment, the transverse ribbon has a corrugated shape,and includes a plurality of creases 166 and 168, such that when theintrauterine device 102 is in the collapsed position, as shown in FIG.4, the transverse ribbon 164 is folded along the creases 166 and 168.

Referring back to FIG. 3A, according to one embodiment, the externalcentral support member 152 and the internal central support member 154are hollow elongate tubes. When a suction is applied to the applicator102, for example from the suction source 112 shown in FIG. 1, fluid,vapor, liquid, and/or tissue may be suctioned through hollow elongatetubular internal support member 154, away from the patient.

According to one aspect, the external flexures 156, 158 and internalflexures 160, 162 include multiple apertures 172. During use inside apatient, the apertures allow fluid, vapor, liquid and/or tissue to flowthrough the flexures and move within the uterus. According to aspects ofthe device, as shown in the illustrative embodiment, the transverseribbon 164 also includes multiple apertures.

FIG. 3B is a perspective view of the portion of an intrauterine therapyapplication device applicator 102 in a deployed position and having amesh array 142, according to an embodiment of the invention. The mesharray 142 surrounds the applicator 102. The mesh array 142 may beknitted from a nylon and spandex knit and plated with gold, silver, oranother conductive material. The mesh array 142 is conformable,permeable, and carries current. The mesh array 142 is attached to theexternal flexures 156, 158 with strands of thread 140 a and 140 b. Thestrands of thread 140 a, 140 b may be nylon. The strands of thread 140a, 140 b are sewn through the mesh array 142 and around the externalflexures 156, 158. Some examples of a mesh array are described in U.S.Pat. No. 6,813,520 to Truckai et al., which is hereby incorporated byreference herein in its entirety.

FIG. 4 is a perspective view of an intrauterine therapy applicationdevice with the applicator 102 illustrated in a collapsed position. Inthe collapsed position, the external flexures 156, 158 and the internalflexures 160, 162 extend laterally parallel with the external 152 andinternal 154 central support members. The transverse ribbon 164 isfolded along the creases 166, 168 shown in FIG. 3A. During use of anintrauterine therapy application device, such as the device 100described with respect to FIG. 1, the applicator 102 is in a collapsedposition inside the sheath 104 while the sheath 104 is inserted throughthe cervix. When the applicator 102 is extended distally from the distalend of the sheath 104, it expands to the deployed position shown in FIG.3A.

According to features of this disclosure, the internal flexures may bedesigned to include at least one flexible section adjacent to one ormore rigid sections. In one embodiment, a flexible section is positionedbetween two more rigid sections. The flexible section facilitatesbending outward, away from the central support member, allowing theinternal flexures to expand laterally away from the central supportmember to create a V-shape. FIG. 5 is a perspective view of anembodiment of an intrauterine therapy application device applicator 202showing an internal central support member 204, external flexures 206,208, and internal flexures 210, 212 having a flexible section and tworigid sections. The first internal flexure 210 and second internalflexure 212 each include at least three sections 210 a, 210 b, 210 c and212 a, 212 b, 212 c. A proximal section 210 a, 212 a of each internalflexure is attached to or coupled to the central support member 204 andhas a first thickness, a middle section 210 b, 212 b of each internalflexure has a second thickness, and a distal section 210 c, 212 c ofeach internal flexure has a third thickness. According to oneembodiment, the second thickness is less than the first thickness andless than the third thickness, so that the middle section 210 b, 212 bis configured to bend more readily than the respective first and thirdsections, which facilitates the flexures 210, 212 to angle laterallyaway from the internal central support member 204. The first sections210 a, 212 a and third sections 210 c, 212 c sections are stiffer thanthe second sections 210 b, 212 b. In one embodiment, the first thicknessis substantially the same as the third thickness, but it is alsocontemplated that the first and third thicknesses can be different.

It is to be understood that stiffness refers to the bendingcharacteristics of a flexure. Regions of a flexure that are moreresistant to bending are considered to be stiffer, or have a greaterstiffness, than regions of a flexure that bend more easily. It isappreciated that several properties of flexure construction can becontrolled to adjust stiffness and create a flexure with two or moreportions, each having a different stiffness. For example, selectedmanufacturing processes can be used to alter a material's modulus ofelasticity. The manufacturing processes can be used selectively ondifferent areas of a flexure to create a flexure with different moduliof elasticity in different areas of the flexure. In another example, aflexure may be constructed of multiple materials, each material having adifferent modulus of elasticity. In a further example, thecross-sectional profile of a flexure, such as the thickness and/or widthof the flexure may be adjusted to create a flexure having multipleportions, each portion having a different stiffness. Adjusting thecross-sectional profile of the flexure locally alters the flexure'sbending moment of inertia, thereby rendering that portion of the flexureeither more resistant to bending or less resistant to bending. Infurther embodiments, other methods and characteristics may be used tocontrol the stiffness of different portions of a flexure.

FIG. 6 is a blown up top elevation view of a portion of an internalflexure 220 having a varying thickness, according to an embodiment ofthe invention. As shown in FIG. 6, internal flexure 220 includes aproximal section 220 a having a first thickness, a middle section 220 bhaving a second thickness, and a distal section 220 c having a thirdthickness. According to one embodiment, the second thickness is lessthan the first thickness and the third thickness, and the middle section220 b is configured to bend. For example, when pressure is applied tothe distal section 220 c of the internal flexure 220, pushing it awayfrom a central support member 204, the internal flexure 220 bends at themiddle section 220 b because the middle section 220 b is less stiff thanthe distal section 220 c. As shown with respect to FIG. 5, the distalsections 210 c, 212 c of the first internal flexure 210 and secondinternal flexure 212 remain relatively straight and rigid, while thelateral angling occurs at the middle sections 210 b, 212 b.

Referring now to FIGS. 7-8, according to another embodiment, theinternal flexures include strain relief portions to decrease thepossibility of undesirable bending or breaking. FIG. 7 is a perspectiveview of an ablation device applicator 302 showing an internal centralsupport member 304, external flexures 306, 308, and internal flexures310, 312. According to aspects of this applicator, the internal flexures310, 312 have varying thickness and include strain relief portions. Theinternal flexures 310, 312 each include a proximal section 310 a, 312 a,a middle section 310 b, 312 b, and a distal section 310 c, 312 c. Theproximal sections 310 a, 312 a and the distal sections 310 c, 312 c eachinclude strain relief portions 314 a, 314 b (See also FIG. 8). Thestrain relief portions 314 a, 314 b are triangular-shaped portionslocated at an end of each section 310 a, 312 a and 310 c, 312 c wherethe proximal sections 310 a, 312 a and the distal sections 310 c, 312 cattach to the middle section 310 b, 312 b, as described in greaterdetail below with respect to FIG. 8.

FIG. 8 is a blown up view of a portion of internal flexure 312 havingvarying thickness and strain relief portions 314 a, 314 b according toan embodiment of the invention. The internal flexure 312 includesproximal section 312 a, middle section 312 b, and distal section 312 c.A distal end 314 a of the proximal section 312 a has a triangular shapeand acts as a strain relief to relieve stress at the interface betweenthe proximal section 312 a and the middle section 312 b. A proximal end314 b of the distal section 312 c similarly has a triangular shape andacts as a strain relief to relieve stress at the interface between thedistal section 312 c and the middle section 312 b. It is appreciatedthat in other embodiments, the strain relief portions 314 a, 314 b maybe other shapes, such as rounded or semi-circular. The middle section312 b is configured to be more flexible than the proximal section 312 aand the distal section 312 c, such that the internal flexure 312 bendsalong the middle section 312 b.

According to the embodiment of FIG. 8, the proximal section 320 a has afirst thickness, the middle section 320 b has a second thickness, andthe distal section 320 c has a third thickness. According to onefeature, the second thickness is less than the first thickness and thesecond thickness is also less than the third thickness. It iscontemplated that the first thickness and the third thickness can besubstantially the same thickness or different thickness.

According to another embodiment, the proximal section 312 a has a firstwidth, the middle section 312 b has a second width, and the distalsection 312 c has a third width. According to one feature, the secondwidth is narrower than the first width, and the second width is narrowerthan the third width. It is contemplated that the first width and thethird width can be substantially the same or different. It is to beappreciated that alternate embodiments can easily be provided where thesecond section is wider than the first and third sections.

Referring to FIG. 7, similar to the internal flexures 210-212illustrated in the embodiment of FIG. 5, the internal flexures 310, 312include at least one flexible section positioned between two stiffersections. The flexible section is configured to bend outward, away fromthe central support member, allowing the distal end of the internalflexures to expand laterally away from the central support member tocreate a V-shape. According to one embodiment, the second sections 310b, 312 b are configured to bend, allowing the internal flexures 310, 312to angle laterally away from the internal central support member 304.The first sections 310 a, 312 a and third sections 310 c, 312 c arestiffer than the second sections 310 b, 312 b. The second sections 310b, 312 b are more flexible so as to facilitate bending at the secondsections 310 b, 312 b. In one example, the first sections 310 a, 312 aand third sections 310 c, 312 c are rigid or substantially rigid.

FIG. 9A is a side view of a section of an internal flexure 400 havingvarying thickness, according to an embodiment of the invention. Theinternal flexure 400 has at least two different thicknesses. Inparticular, a thickness of the middle section 406 is less than athickness of the rest of the flexure 400. It is contemplated that therest of the flexure can have substantially the same or differentthicknesses. In the illustrated embodiment, the proximal 402 and distal404 sections of the flexure 400 have substantially the same thickness,and the first transition area 408 and second transition area 410 havesubstantially the same thickness as the proximal 402 and distal 404sections. In one example, the transition areas 408 and 410 are welded tothe section 406. It is to be appreciated that the areas of differentthickness can also be provided by other structures. For example, each ofthe transition areas 408 and 410 may be etched together, such that eachtransition area 408 and 410 is a single piece of material. In anotherexample, the entire flexure 400 is etched as a single piece of material.In a further example, the transition areas 408 and 410 each include twolayers of stacked material that are bonded together by varioustechniques known in the art. For example, the first transition area 408includes a first bottom layer 418 and first top layer 420, and thesecond transition area 410 includes a second bottom layer 428 and secondtop layer 430. In some embodiments, the internal flexure 400 may includeadditional transitional areas between the middle section 406 and theproximal section 402 and distal section 404.

For example, FIG. 9B is a side view of a section of an internal flexure450 having two tapering thickness sections 458, 460, according toanother embodiment of the invention. In this embodiment, a thickness ofa middle section 456 is less than a thickness of the rest of the flexure450, and a thickness of the proximal section 452 and a thickness of thedistal section 454 is greater than the thickness of the rest of theflexure 450. It is contemplated that the thickness of the proximalsection and the distal section can be the same or different. Theinternal flexure also includes a first transitional region 458,positioned between the proximal section 452 and the middle section 456,which has a varying thickness that tapers from the thickness of theproximal section 452 to the thickness of the middle section 456.Similarly, the second internal flexure also includes a transitionalregion 460, positioned between the distal section 454 and the middlesection 456, which has a varying thickness that tapers from thethickness of the distal section 454 to the thickness of the middlesection 456.

It is to be appreciated that varying the thicknesses of the internalflexure 400 of FIG. 9A and the internal flexure 450 of FIG. 9B providesfor the overall diameter of the intrauterine device applicator in acollapsed position to be decreased, while maintaining its strength andstiffness. Decreasing the overall diameter in a collapsed position, ofthe applicator allows for use of a smaller-diameter sheath. A sheathwith a smaller outer diameter may also reduce patient discomfort, andalso decrease the potential for cervical injury during insertion. Thus,one advantage of the varying thicknesses of the internal flexures 400and 450 is that they provide for the outer diameter of the applicator tobe decreased, while maintaining the reliability of the deployment of theapplicator from the sheath and the retraction of the applicator backinto the sheath.

FIG. 10 is a side elevation view of another embodiment of a portion ofan intrauterine therapy application device 480, including a centralsupport member 482 and an internal flexure 484 having a first section486 and a second section 488. According to aspects of the disclosure, itmay be desirable to control both the lateral and vertical flexibility ofthe internal flexures of the applicator. This can be accomplished withthe internal flexure 484 of FIG. 10. The first section 486 is attachedto the central support member 482 and the second section 488 is attachedto a proximal portion 486 a of the first section 486 and extendsparallel to the first section 486. The first section 486 includes amiddle portion 486 b, positioned just past the distal end 482 a of thecentral support member 482. The middle portion 486 b of the firstsection 486 curves inward away from the second section 488 of theinternal flexure 484, extends longitudinally, parallel to the secondsection 488 but positioned a distance away from the second section 488,and then curves back toward the second section 488 of the internalflexure 484. The distal portion 486 c of the first section 486 of theinternal flexure 484 is attached to the second section 488 of theinternal flexure 484. According to one feature, the shape of the firstsection 486, including the curved middle portion 486 b, increases thedurability and reliability of the internal flexure 484.

FIG. 11A shows the first section 486 of the internal flexure 484 in arelaxed position and FIG. 11B shows the first section 486 of theinternal flexure 484 in an expanded position. According to one feature,the jog in the middle portion 486 b of the first section 486 isolatesthe flexibility and rigidity of the first section 486 to selected partsof the first section 486 of the flexure. For example, first bend 490 aand second bend 490 b provide areas of flexibility.

In one example, each of the stacked sections 486, 488 is half thethickness of an internal flexure without such stacked sections, so thatthe thickness of the internal flexure 484 is about the same as thethickness of a single-layer internal flexure. For example, the internalflexure 484 can be a substitute for the internal flexures 160, 162 ofFIG. 3A. According to one feature, the internal flexure 484 formed fromtwo stacked sections 486 and 488 has a decreased lateral stiffnesscompared to an internal flexure formed from a single layer. According toanother feature, the internal flexure 484 formed from two stackedsections 486 and 488 has about the same vertical stiffness as aninternal flexure formed from a single layer. Thus, the internal flexureof FIG. 10 has a decreased lateral stiffness and a vertical stiffnessthat is about the same as the internal flexure of the embodiment of FIG.3A

FIG. 12 is a flow chart showing one embodiment of a method 500 ofmanufacturing an intrauterine device. At step 502, a central supportmember is provided. At step 504, first and second internal flexures areformed using a photo etching (or photochemical machining) process. Thefirst and second internal flexures include a first section having afirst stiffness, a second section having a second stiffness, and a thirdsection having a third stiffness, with the second stiffness moreflexible than the first and third stiffnesses, according to the variousembodiments discussed herein.

In one example, the photo etching process includes printing the shape ofone or more internal flexures onto optically clear and dimensionallystable photographic film. The photographic film shows a negative imageof the internal flexures, such that the areas to be etched are black,and the area that will become the internal flexures are clear.Generally, two sheets of photographic film are used. The two sheets areoptically and mechanically registered to form the top and bottom halvesof the part to be etched (the internal flexure).

Metal sheets for etching into internal flexures are cut to size, cleanedand then laminated on both sides with a UV-sensitive photoresist. Acoated metal sheet is placed between the two sheets of photographicfilm. A vacuum is created to ensure intimate contact between thephotographic film and the coated metal sheet. The coated metal sheet isthen exposed in UV light that allows the areas in the clear sections ofthe photographic film to be hardened. After exposure, the plate isdeveloped by washing away the unexposed resist, leaving the areas to beetched unprotected.

An etchant is sprayed on both sides of the developed plate, causing theunprotected areas of the plate to corrode away, leaving the photo etchedinternal flexures. The etchant may be an aqueous solution of acid, suchas ferric chloride. In one example, before spraying the etchant on thedeveloped plate, the etchant is heated. The etching process may takeplace in a multi-chambered machine that has driven-wheel conveyors tomove the plates and arrays of spray nozzles above and below the plates.According to one feature, the top and bottom of the developed plate canbe etched at different rates. In one example, etching the top and bottomof the developed plate at different rates allows for better control overthe thickness of the resulting internal flexures, and allows for bettercontrol over the thickness of the flexible section of the internalflexures. After etching the developed plate, it is neutralized andrinsed, the remaining resist is removed, and the sheet of internalflexures is cleaned and dried. According to various embodiments, thephoto etching process described above may be used to form any part ofthe intrauterine device.

Still referring to FIG. 12, at step 506, the first and second externalflexures are provided. The first and second external flexures may beformed using a photo etching process as described above with respect toforming the first and second internal flexures. At step 508, a firstsection of each internal flexure is attached to the central supportmember. At step 510, a proximal end of each of the first and secondexternal flexures is attached to the central support member. At step512, a distal end of each of the first and second flexures is attachedto the third section of the first and second internal flexures.Attachment may be done by any means known to those of skill in the art.

According to another embodiment, a stamping process may be used to formthe internal flexures. A stamping process would involve producing a flatpattern of metal using a punch and die method, punching out the selectedpattern. The resulting flat piece of metal may be locally deformed usinga coining process, which can be used to change the shape of the piece ofmetal to have a higher bending moment of inertia in selected regions,thereby increasing the stiffness of the selected regions.

FIGS. 13-16 show a portion of another embodiment of a medical deviceapplicator including a notched tubular central support member and matinginternal flexures. The intrauterine device applicator 600 includes atubular proximal central support member 602, internal flexures 606 and608, and a distal central support member 604. The internal flexures 606and 608 are inserted into notches in the proximal central support member602, and welded in place. For example, FIG. 14 shows the proximalcentral support member 602, including notches 610 and 612. The proximalend of an internal flexure, such as the proximal end 606 a of theinternal flexure 606 shown in FIG. 15 is inserted into the notches 610,612 of the central support member 602 shown in FIG. 14. The proximal endof the internal flexure can be secured to the central support member.For example, the internal flexure may be welded to the central supportmember.

FIG. 16 shows an exploded view of one end of the combination of thedistal central support member 604 and the internal flexures 606 and 608.As shown in FIG. 16, the internal flexures 606 and 608 may be coupled tothe distal central support member 604. The combination of the internalflexures 606 and 608 and the central support member 604 may be coupledto the proximal central support member 602. For example, the combinationt including internal flexures 606 and 608 and the central support member604 may be inserted into the proximal central support member 602 andsecured in place by various techniques known to those of skill in theart.

FIG. 17 shows a portion of another embodiment of an intrauterine deviceapplicator 700 having central support member 702, internal flexures 704,706, 708, and 710, and external flexures 720 and 722. Internal flexures704, 706 are stacked, and internal flexures 708, 710 are stacked.Internal flexures 704,708 are joined to the central support member 702at proximal locations 704 a and 708 a, respectively, and internalflexures 706, 710 are joined to the central support member 702 atproximal locations 706 a and 710 a, respectively. Internal flexures 704,706 are joined to external flexure 720 at a distal location 704 c, andinternal flexures 708, 710 are joined to external flexure 722 at distallocation 708 c. As shown in FIG. 17, the stacked pairs of internalflexures 704, 706 can be joined at a middle location 704 b. Similarly,internal flexures 708, 710 can be joined at a middle location 708 b. Itis appreciated that joining methods and structure may include any ofwelding, tying, bonding, or any other joining method and structure usedin the art.

According to one embodiment, the first 704 and second 706 stackedsections are both the same length. For this embodiment, in the deployedstate, internal flexure 704 is forced to bend at a slightly differentradius than internal flexure 706, causing internal flexures 704, 706 toseparate in the distal region, as shown in FIG. 17. It is to beunderstood that according to this disclosure, this separation behavioris herein referred to as oil-canning. It is to be appreciated that otherembodiments as disclosed herein do not exhibit such oil-canning. Forexample, the embodiments shown in FIGS. 10, 11A and 11B preventoil-canning by introducing a local compliant region that allows for theend-to-end length of the flexure to change slightly in an intentionalmanner.

FIG. 18 shows another embodiment of an intrauterine device applicator750 having two sets of internal flexures, shown in an expanded position.The intrauterine device 750 includes a proximal central support member752, a distal central support member 754, external flexures 756, 758, afirst set of internal flexures 760, 762 and a second set of internalflexures 764, 766. The proximal ends 760 a, 762 a of each flexure of thefirst set of internal flexures 760, 762 are coupled to the distalcentral support member 754 at a first location 754 a. The distal ends760 b, 762 b of each flexure of the first set of internal flexures 760,762 are coupled to a middle portion 756 b, 758 b the external flexures756, 758. The proximal ends 764 a, 766 a of the second set of internalflexures 764, 766 are coupled to the distal central support member 754at a second location 754 b, which second location is distal to the firstlocation. The distal ends 764 b, 766 b of the second set of internalflexures 764, 766 are coupled to the distal ends 756 c, 758 c of theexternal flexures 756, 758. According to one feature, by utilizing threeor more flexures and/or strategic location of the joints of theflexures, the shape of the intrauterine device in the expanded positioncan be controlled to reliably match complex anatomy better than whenusing a more basic two-flexure design. In one embodiment, the internalflexures 760, 762, 764, 766 each have a thickness about half as thick asthe internal flexures 160, 162 shown in FIG. 3A.

According to any of the embodiments disclosed herein, the ribbon 164shown by way of example in FIGS. 3A-3B may be replaced with alternativemesh support designs. It is appreciated that the ribbon 164 shown inFIGS. 3A-3B takes up a large amount of cross-sectional space in theretracted position, as shown by way of example in FIG. 4. According tovarious embodiments, FIGS. 19A-B and 20A-C show intrauterine deviceswith alternative embodiments of arms to support a mesh array. The armsmay be used in place of a ribbon to reduce the outer diameter of anintrauterine device in a retracted position. According to variousexamples, the mesh support arms mechanically support the distal end 818of the mesh array, preventing the mesh array from pulling backproximally and/or toward the central support members. Additionally, themesh support arms provide vertical support, mechanically separating thetop of the mesh array from the bottom of the mesh array, which may helpprevent an alternating current short through the mesh array when energyis delivered to the medical device after it is inserted in a patient.

FIG. 19A is a perspective view of a portion of an embodiment of anintrauterine ablation device applicator 800 in a deployed position. Theapplicator 800 includes a central support member 802, external flexures804, 806, internal flexures 808, 810, arms 814, 816, and a centralbridge 812. The proximal ends 814 a, 816 a of the arms 814, 816 arecoupled to the central support member 802, and the arms 814, 816 extendlaterally away from the central support member 802. The attachment ofthe proximal ends 814 a, 816 a of the arms 814, 816 to the centralsupport member 802 provides flexibility to the arms for lateralextension.

As shown in FIG. 19A, each end of a central bridge 812 is coupled to amiddle portion 814 b, 816 b of each arm 814, 816. In an expandedposition, the center 812 a of the central bridge 812 extendslongitudinally beyond the distal end 802 a of the central support member802. When a mesh array is positioned about the intrauterine ablationdevice applicator 800, as shown in FIG. 19B, the center 812 a of thecentral bridge 812 supports the distal end 818 of the mesh array.According to one embodiment, the arms 814, 816 and the central bridge812 can be compressed toward the center line of the central supportmember 802 for retraction into a sheath, such as the sheath 104 of FIG.1.

According to one feature, attaching the arms 814, 816 to a more proximallocation than the distal end of the external flexures, in comparison towhere the ribbon 164 of FIG. 3A is attached, results in a device with asmaller outer diameter in a retracted position. In a retracted position,the ribbon 164 of the illustrative embodiment of FIG. 3A is foldedmultiple times, resulting in eight layers of stacked ribbon material. Incontrast, the applicator shown in FIG. 19A includes four layers of arm814, 816 and central bridge 812 material in the retracted position toprovide a reduced diameter in the retracted position. According to oneembodiment, the arms 814, 816 and the central bridge 812 are coated inan electrically insulating coating, such as parylene. The coating on thesurfaces of the arms 814, 816 and the central bridge 812 increases thethickness of the arms 814, 816 and the central bridge 812 (or, when usedon the applicator 102, increases the thickness of the folded ribbon164).

FIG. 20A is a perspective view of a portion of another embodiment of anintrauterine ablation device applicator 850 having arms 862, 864 shownin an expanded position. The applicator 850 includes a central supportmember 852, external flexures 854, 856, internal flexures 858, 860, andarms 862, 864. The proximal ends 862 a, 864 a of the arms 862, 864 arecoupled to a middle portion 858 b, 860 b of the internal flexures 858,860. The arms 862, 864 curve laterally outward, and then curve back intoward the center line defined by the central support member 852. Thedistal ends 862 b, 864 b of the arms 862, 864 are directed inward towardthe center line. FIG. 20B is an elevation view of a portion of theintrauterine ablation device applicator 850 of FIG. 20A with a mesharray cover 868 disposed thereabout. FIG. 20C is an elevation view of aportion of the intrauterine ablation device applicator 850 of FIG. 20Ahaving a mesh array anchored to the arms 862, 864 in multiple locations870 a-d, 872 a-d. By anchoring the arms to the array in one or morelocations, the system relies on the combined strength of the armsinteracting with the array, providing improved mechanical strength androbustness of the system without increasing the size of the arms.According to one feature, the arms 862, 864 prevent the top and bottomparts of the mesh array from coming in contact with one another.According to another feature, the arms 862, 864 prop up the distal endof the mesh array.

As discussed above, decreasing the thickness of the structure thatmaintains the extension of the mesh array at the distal end of theapplicator 852 allows for a decreased outer diameter of a sheathenclosing the applicator 852 in a retracted position. The applicator 852includes only two arms 862, 864, which are attached to the internalflexures 858, 860 distal to the distal end of the central support member852. Thus, the applicator 852 can be positioned within a substantiallysmaller diameter sheath in the retracted position than, for example, theapplicator 102 shown in FIGS. 3A, 3B, and FIG. 4.

Having described above several aspects of at least one embodiment, it isto be appreciated various alterations, modifications, and improvementswill readily occur to those skilled in the art. Such alterations,modifications, and improvements are intended to be part of thisdisclosure and are intended to be within the scope of the invention.Accordingly, the foregoing description and drawings are by way ofexample only.

What is claimed is:
 1. An intrauterine device, comprising: a centralsupport member; first and second inner flexures, each having a proximalportion, a middle portion, and distal portion, and wherein the proximalportion of each inner flexure is coupled to the central support member;an arm member, having a proximal portion and a distal portion, whereinthe proximal portion of the arm member is coupled to the middle portionof the first inner flexure at a first location, and wherein the firstinner flexure and the arm member extend distally from the first locationand form an acute angle with each other; and first and second outerflexures, each having a proximal end and a distal end, wherein therespective proximal ends of the first and second outer flexures arecoupled to the central support member, and wherein the respective distalends of the first and second outer flexures are coupled to therespective distal portions of the respective first and second innerflexures, wherein the first and second outer flexures, in combinationwith the arm member and in further combination with the first and secondinner flexures comprise a delivery configuration for transcervicalinsertion, and a deployed configuration for deployment in a uterinecavity.
 2. The intrauterine device of claim 1, wherein the arm membercomprises an arcuate configuration in the deployed configuration.
 3. Theintrauterine device of claim 1, further comprising a second arm member,the second arm member having a proximal portion and a distal portion,and wherein the proximal portion of the second arm member is coupled tothe middle portion of the second inner flexure at a second location, andwherein the second inner flexure and the second arm member distally fromthe second location and form an acute angle with each other.
 4. Theintrauterine device of claim 3, wherein the arm member and second armmember comprise respective concave inner surfaces facing each other, andrespective convex outer surfaces facing the respective first and secondinner flexures, in the deployed configuration.
 5. The intrauterinedevice of claim 3, wherein the arm member and second arm member areconfigured to support a mesh array.
 6. The intrauterine device of claim5, wherein the arm member and second arm member are coupled to the mesharray and, when in the deployed configuration, the respective distalportions of the arm member and second arm member are configured toassist the mesh array to contact a fundal wall of a uterus.
 7. Theintrauterine device of claim 1, wherein the combined flexures and armmember are parallel and adjacently disposed to the central supportmember in the delivery configuration, and the combined flexures and armmember flex away from the central support member in the deployment.